1. Field of the Invention
The present invention is broadly concerned with an improved emergency light fixture which is designed for essential flush mounting in a wall or ceiling but which is automatically deployed to provide illumination in the event of an emergency. More particularly, the invention pertains to such an emergency light fixture which includes a housing for an illumination assembly with a selectively openable cover; the cover is movable through a servo-motor and crank, thereby completely eliminating the need for limit switches in the fixture. A special cover hinge also causes the cover to both pivot and translate during movement thereof.
2. Description of the Prior Art
Office buildings and other similar structures are universally provided with emergency lighting fixtures designed to illuminate in the event of a fire or other emergency. For example, battery-operated fixtures are located in stairwells and are often surface-mounted. While these units do serve an important purpose, they are considered unsightly and many designers hesitate to use them in formal offices or other settings where aesthetics are a consideration.
It has also been known to provide flush-mounted emergency light fixtures having a pivotal cover. In such units, an illumination assembly is located in a recessed housing or the like and when an emergency occurs, the cover is pivoted open and the recessed lamps are illuminated. Deployment of these prior flush-mounted emergency lighting fixtures is typically achieved by means of an electric motor and various limit switches to stop the operation of the cover in both the open and close directions. However, upon failure of the limit switches, these units tend to self-destruct and become unusable. An additional problem with these prior units is that it is difficult to provide a cover opening mechanism which will assure that the cover opens in a smooth, reliable and controlled way even after extended periods of non-use.
There is accordingly a need in the art for an improved emergency lighting fixture which eliminates all potentially troublesome limit switches and gives accurate and reliable cover movement at all times.
The present invention overcomes the problems outlined above, and provides an improved emergency light fixture of the flush-mounted variety. Broadly speaking, the fixture of the invention includes a housing adapted for placement in a wall or ceiling aperture and presenting an opening, with a shiftable cover movable between a closed position and an open position; an illumination lamp is located within the housing when the cover is in its closed position, but preferably is moved at least partially out of the housing when the cover is open. The overall fixture further includes an operating assembly coupled with the cover and lamp in order to selectively move the cover and operate the lamp. The assembly includes a servo-motor having an output, with an operator connected between the output and the cover for moving the cover towards its open and closed positions. A control circuit is also provided which is coupled with an emergency power source and connected with the servo-motor and lamp respectively.
In preferred forms, a pair of illumination lamps are provided, and these are connected to the cover in order to provide a gravity assist during cover opening and to insure that the full illumination power of the lamps is utilized. The cover is secured to the housing by means of a special hinge which causes the cover to both pivot and translate relative to the housing during cover movement. This special hinge comprises first and second hinge parts respectively connected to the housing and cover, with a hinge pin interconnecting the hinge parts; the first hinge part is connected with the housing in a floating manner and translates during cover movement by virtue of a slot/connector arrangement between the hinge part and housing.
Use of a servo-motor and appropriate control circuitry permits the cover to be accurately moved between its open and close positions without the need for limit switches, and the preferred floating hinge arrangement facilitates reliable cover control.